Deaerating steam trap



Sept. 8, 1964 A. F. M CORMACK, JR 3,147,920

DEAERATING STEAM TRAP Filed March 20, 1962 i -26 INVENTOR. AUSTIN F. m copmcmp.

: I M04 ,7 ,4m41a6%z ATTOF? N EYS 3,147,920 DEAERATING STEAM TRAP Austin F. McCormack, In, 1414 Bella Vista Drive, Dallas, Tex. Filed Mar. 20, 1962, Ser. No. 181,115 8 Claims. (Cl. 236-53) This invention relates to steam traps and in particular to a deaerating steam trap of the type used in steam heating systems.

Steam traps are conventionally used in steam heating systems and are automatically operated to trap or retain steam in the heating apparatus or piping system until its latent heat has been dissipated and then to permit the condensate from the steam to accumulate for discharge to the return line of the heating system. A particular disadvantage to such a system is the continuous expense of replacing piping systems because of corrosion. This corrosion is principally caused by the presence of carbon dioxide in the condensate as well as oxygen and other non-condensible gases. The continuous forming of corrosion results in a corresponding continuing decrease in the overall efliciency of the heating system.

Accordingly, an object of this invention is to preclude a decrease in the efiiciency of steam apparatus.

United States Patent Another object of this invention is to eliminate corrosive elements from the heating medium in the return line of a steam heating system.

It is another object of this invention to incorporate a gas separation chamber in a steam trap.

This invention has another object in that the non-condensible gases are separated from the condensate in a steam trap.

This invention has another object in that a condenser coil is combined with a steam trap.

It is still another object of this invention to position a condenser coil between a steam trap and a thermostatic escape valve without interfering with normal steam trap operation.

A further object of this invention is to remove noncondensible gases from the discharged condensate in a steam trap before such condensate is delivered to the steam trap outlet.

A further object of this invention is to recover condensate from steam flashed during operation of a steam trap.

It is still a further object of this invention to separate and remove gases from steam flashed during operation of a steam trap.

Additional features and advantages of this invention will become apparent from the following description of a preferred embodiment shown in the single figure of the drawing which is a vertical section view of a steam trap and its associated elements.

As is illustrated in the drawing, the steam trap comprises a generally hollow body 10 having an inlet 12 and a pair of outlets 14 and 16. The interior of the body 10 forms a condensate collection chamber 18 that is separated by a partition wall 20, the lower portion of which is provided with a removable filter plug unit 22 so positioned as to filter the flow from the inlet 12 to the chamber 18.

The condensate collection chamber collects condensed moisture from the steam entering the inlet 12 and such condensate supports a bucket 24 in a buoyant manner. A valve plate 26 is integrated to the bottom of the bucket 24 as by a plurality of mounting studs and nuts 28 (only one being shown). The upper end of each mounting stud 26 is pivoted to a strap 30 fixed to the valve plate 26 which is thus assured of aligned seating even though the bucket 24 may be slightly tilted due to the buoyant forces.

The upper part of chamber 18 is defined by a partition wall 32 centrally formed with a downwardly extending hollow tubular member 34, the lower edge of which forms 3,147,920 Patented Sept. 8, 1964 a valve seat 36 for the valve plate 26. The top surface of partition wall 32 and the opposite interior surfaces of the body 10 define a condensate outlet chamber 38 which communicates with the outlets 14 and 16.

A valve stem 40 has its lower end adjustably threaded through the valve plate 26 as is apparent from the crosssection seen through the rectangular opening in the strap 30. The valve stem 40 is disposed in the tube 34 and has a conical valve member 42 fixed on its upper end. The valve 42 cooperates with an orifice fitting 44 threaded into the partition 32 so as to be in axial alignment with the outlet 14. The valve plate 26 and the valve 42 are simultaneously moved in response to the rise and fall of the bucket 24 whose vertical movement is stabilized about its central axis by means of a plurality of stabilizing pins 46 (only one being shown) which are adjustably threaded into the undersurface of partition 32. Each pin 46 extends into the bucket 24 so as to be slightly spaced from the interior of the bucket 24.

In addition to communicating with the collection chamber 18, the steam and condensate inlet 12 also communicate with the condensate outlet chamber 38 by means of a bypass orifice 48 which is controlled by a bellows type valve 50. A mounting plug 52 carries the bellows valve 50 in axial alignment with the orifice 48 and in such a location as to be responsive to steam entering the inlet 12. The orifice 48 and valve 50 constitute an air bypass to condensate outlet chamber 38, which is thermostatically con trolled. The valve 50 is expanded to a closed position in response to the inlet temperature of the steam; conversely a reduction of the inlet temperature causes contraction of the bellows valve 56 and permits air to pass directly to the condensate outlet chamber 38.

A vertically disposed conduit, forming a separation chamber 54, has one end connected to the outlet 14 and an opposite end connected to a capillary coil 56 made of any suitable thin walled tube such as copper tubing. The capillary coil 56 forms a condenser coil that communicates with a thermostatic release valve 58 which is automatically operated at a predetermined temperature to expel non-condensible gases to the atmosphere. In this particular installation, the thermostatic release valve 56 includes a bellows type valve member 60 that is normally closed on a valve seat 62 and is moved away from such seat upon contraction in response to a predetermined temperature.

The present invention is particularly adaptable for use in a steam heating system and in such operation, the inlet 12 is connected to a steam condensate connection and the outlet 16 is connected to the return line of the system. The steam trap performs the basic function of preventing the steam from passing through the trap itself while permitting the collected condensate to be dumped into the return line. densible gases as oxygen, carbon dioxide and nitrogen; the oxygen and carbon dioxide are basic causes of return line corrosion in steam heating systems but such corrosive elements are eliminated as will become more apparent in the following description of the sequence of operation.

In operation, the condensate will collect in the chamber 18 from which it spills over into the bucket 24. As the bucket 24 begins to fill with condensate, its buoyancy is overcome and the bucket 24 begins to sink. The downward movement of the bucket 24 simultaneously moves valve plate 26 away from valve seat 36 and conical valve 42 away from orifice seat 44. The condensate in the bucket 24 is then forced by the steam pressure acting on its surface to rush up through the hollow tube 34 and is discharged through the orifice fitting 44. The valve member 42 and valve seat 44 constitute a variable orifice or atomizing valve which increases the velocity and decreases the pressure of the discharged condensate. Be-

This collected condensate includes such non-con cause of the axial alignment of the outlet 14 with the orifice 44, the discharged condensate is projected into the conduit chamber 54 and because of the atomizing operation, the condensate is discharged with its non-condensible gases commencing to separate from the condensate. The high velocity of this sprayed discharge into the separation chamber 54 accomplishes the separation of the non-condensible gases and the condensate. The condenser coil 56 collects the non-condensible gases which are intermittently expelled to the atmosphere by the automatic thermostatic valve 58 whenever the temperature reaches a predetermined point. The condensate falls back down the conduit chamber 54 to the condensate outlet chamber 38 whence it is delivered to the condensate outlet 16 in a condition substantially free of non-condensible gases so that the return piping of the heating system is not subjected to any corrosive action by the condensate.

It is known that condensate at a high pressure and temperature will flash into steam as a result of a pressure drop. The decrease in pressure as the condensate passes through the variable orifice 44 may cause flashing depending upon the temperature of the condensate and the steam pressure acting on the surface of the condensate in the bucket. Inasmuch as carbon dioxide is freely separated from flashed steam by condensing out the steam, the present invention has the additional advantage of recovering the condensed steam that would normally be vented to the atmosphere. The flashed steam is discharged into the conduit chamber 54 and is condensed as condensate by the cooling coil 56; such condensate is recoverable by falling back down the conduit chamber 54 to the condensate outlet chamber 38. The top of the coil 56 collects the non-condensible gases, e.g. carbon dioxide, from the flashed steam and cools them for release to the atmosphere by the thermostatic valve 58.

While the present invention has been described in connection with a bucket type steam trap, it is apparent that it may be utilized with other types of steam traps. Inasmuch as the preferred embodiment of the invention is subject to many modifications and changes in structural details, it is intended that all matter contained in the foregoing description and illustrated in the drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In an automatic device for removing non-condensible gases from steam condensate, the combination comprising a steam trap for collecting and discharging condensate from steam apparatus, a temperature controlled valve device remotely connected to the discharge side of said trap operative to vent gases to the atmosphere when temperature at said valve device is relatively low, and means comprising a separation chamber for separating corrosive gases from condensate operatively connected between said steam trap and said valve device to separate gases from condensate discharged by said steam trap and to deliver such separate gases to said valve device.

2. The combination as recited in claim 1 wherein said separation chamber includes a condenser coil.

3. In a steam trap device, the combination comprising a steam trap body having inlet and outlet means separated by a chamber for collecting liquid, valve means for releasing collected liquid from said chamber in the form of a discharge, and means disposed upstream of said outlet means and including a separate outlet for gases on the downstream side of the trap for purging non-condensible gases from such discharge before delivery of condensate to said outlet means. I

4. The combination recited in claim 3 wherein said means disposed upstream of said outlet means is positioned to receive the discharged liquid directly from said valve means. I

5. In a deaerating steam trap device, the combination comprising a steam trap casing having inlet and outlet means with a chamber therebetween for collecting condensed liquid from a flow entering said inlet means, valve means operable to discharge such liquid from said chamber at a high velocity in the form of a spray, separation chamber means positioned to receive and separate the discharged spray into non-condensible gases and liquid condensate, and means separate from said outlet means to remove such non-condensible gases to the atmosphere, said separation chamber means being operative to permit such liquid condensate to flow to said outlet means.

6. The combination as recited in claim 5 wherein said separation chamber means includes a condenser coil.

7. In a steam trap device, the combination comprising a steam trap body having an inlet and an outlet with a condensate collection chamber therebetween, atomizing valve means for discharging the collected condensate from said chamber at a high velocity in the form of a spray, a thermostatically operated bypass communicating with said inlet and preventing a flow of steam but permitting a flow of air to said outlet, an additional outlet means for said steam trap body being disposed upstream of said outlet and in alignment with said atomizing valve means so as to receive the spray discharged thereby, gas separation means including a condenser coil and a chamber communicating with said additional outlet means for separating gases from said discharged spray and recovering condensate therefrom, said chamber permitting the recovered condensate to flow back through said additional outlet means for delivery to said outlet, and means communicating with said condenser coil to remove the separated gases to the atmosphere.

8. The combination as recited in claim 7 wherein said last named means comprises a thermostatically operated valve.

References Cited in the file of this patent UNITED STATES PATENTS 1,191,342 Pendleton July 18, 1916 2,370,296 Ehretsman et al Feb. 27, 1945 FOREIGN PATENTS 1,025,896 Germany Mar. 13, 1958 

1. IN AN AUTOMATIC DEVICE FOR REMOVING NON-CONDENSIBLE GASES FROM STEAM CONDENSATE, THE COMBINATION COMPRISING A STEAM TRAP FOR COLLECTING AND DISCHARGING CONDENSATE FROM STEAM APPARATUS, A TEMPERATURE CONTROLLED VALVE DEVICE REMOTELY CONNECTED TO THE DISCHARGE SIDE OF SAID TRAP OPERATIVE TO VENT GASES TO THE ATMOSPHERE WHEN TEMPERATURE AT SAID VALVE DEVICE IS RELATIVELY LOW, AND MEANS COMPRISING A SEPARATION CHAMBER FOR SEPARATING CORROSIVE GASES FROM CONDENSATE OPERATIVELY CONNECTED BETWEEN SAID STEAM TRAP AND SAID VALVE DEVICE TO SEPA- 